Directrix for turbines and the like



Sept. 11, 1923. 1,467,325

V. KAPLAN DIRECTRIX FOR TURBINES AND THELIKE Filed Dec. 17, 1914 2 Sheets-Sheet l M "ET:

Sept. 11, 1923.

V. KAPLAN DIRECTRIX FOR TURBINES AND THE LIKE Filed Dec;

17, 1 914 2 Sheets-Sheet 2 Fizz/ewe can also leave the guide vanes betweentheir lower edges.-

-' If the turb'ne is adaptedfor a-p'ump, I

VICTOR KAPLAH, Q1 BRU'NNE, AUSTRIA.

DIRECTEIX FOR TURBINES AND THE LTKE.

Application filed December 1 7, 1914. Serial No. 877,782.

To all-whomz'tmay concern:

Be it known that I, Dr. Vro'ron a subject of the Emperor of .Austria, and resident of Brunne, Austria, have invented. certain new and useful Improvements in Directrixes for Turbines and the like (for which I have filed an application in Ger many Sept. 23, 1914), of which the following is a specification;

In my application-Serial No. 803,334 filed Nov. 26, 1913 (Patent 1,399,059), I have described a turbine machine (water, steam or gas-turbine, turbine pump or blower), the

"guide wheel of which is arranged in such a manner,thatthe fluid enters or leaves the guide wheel in a radial or substantially radial direction.

The runner wheel of the said machine is wholly or for the most part provided with axial'flow runner-spaces, lo-' cated at a convenient distance below the lower edges of the guide vanes. If'therefore" the turbine works for instance as a water turbine, the water must be materially deide vanes from its flected betweenfthe radial entrance direction, because the water have shown inmy -said application, that.

onlya reverse of flow is required. The

ma or amount of fluid flows through'the runner wheel in a substantially axial direction, and is deflected [into the guide wheel and leaves' said. wheel illa substantially radial direction.

The advantages produced by such a 0015- 'bination may briefly be characterized asan improvement of the guiding. of the fluid" and a reduction of'its frictional resistances.

The principal'object of my present inventionis to reduce still further the frictional resistances and thus to increase the specific mitted by. a guide wheel provided with m number of revolutions. Another object is to prevent as far as possible the lowering of the eflicicncy, if the admission off-fluid.

changes from time to time. A further object is to simplify the manufactureof the guide vanes, and to reduce the power needed for the adjusting of the regulating means.

These improvements are obtained through a'special arrangement and shape of the space adjacent to the outlet edges of the guide vanes and by avoiding the usual cellshaped form, at least along a part of the bladesof the runner wheel, as is hereinafter fully described, illustrated in the accompa-' KAPLA The guide- (Fig. 1) has been removed. Fig. 3 shows .the left hand side of a twin turbine wheel also chiefly provided with axial-flow runner spaces'(R Fig. 4 shows the combination of a radial flow guidewheel and an axial flow runner wheel. Fig. 5 is a twin turbine showing a radial flow guide wheel and two" axial flow runner wheels. Fig. 6 is the section of a flow surface (2 2 Fig. 4) with two adjacent runner blades spread out in a plane. a

The representation of the Figures (15) is nearly the same as that shown in my above said prior application, the novel features only are specifically shown. To simplify the specification the following; description chiefly refers to water turbines, but it is clear that my invention can also be utilized for. all other klnds of turbines, such as above mentioned;

It is well-known thatthe. frictional losses depend not only on the area of the wetted' bladesurface, but also on the length of the hydraulic flow. For this reason the frictional losses are the greater, the shorter the distance chosen between the outer edges of the guide .vanesand the turbine. axis, because the clearance between the vanes dimjnishestowards the axis:

' A diminution of the friction losses can therefore'be obtained, ifin arunner wheel of my said prior application the fluid is advanes, the lower. edges of which .do not project materially or not at allover the 'wall .of

the suction tube. It is known that such a guide wheel is adapted for radial turbines and also for Francis-turbines. The guide vanes, S thereon are generally movable as is indicated in Eigs. (1-5), for the'purpose of regulating the admission of water.

lide vanes.

But a distinct difference between the shown in my said'priorapplication and those of my present invention will be seen in the drawings, because of the fact, that the outlet edges a, 0 of the guide vanes reach only so far towards the wall of the aginary rim L shown in broken lines, that this runner wheel is sub-divided into two well-known turbine wheels, of which the one, adapted with the-radial fio'w runner spaces R is similar to a Francis-wheel, while theother provided with the axial flow spaces R resembles a Jonval-wheel.

In my 'said priorapplication, the radial 'flow runner spaces R are so insignificant that they may be quite dispensed with, as is indicated in Figs. 4c and 5 of the drawings of the present application. With such a combination of a guide wheel and a runner wheel the flow of fluid proceeds as follows:

Owing to the guide vanes S the water is forced to leave the outlet edges of the guide vanes by the outlet angles, required for a smoothflow, and to enter the space R, in a substantially radial direction, that is with a meridian velocity having the same direction. In said space either the major portion or the whole amount of water is deflected from its radial entrance direction, and flows in a substantially axial direction into the runner wheel. If a single runner'wheel is provided as is shown in Figs. 1 and 4, the above mentioned deflection is indicated by the arrows 2. In a twin turbine (Figs. 3 and 5) .said

' deflection is indicated by the arrows 2 and vided for by the emplo ym 3. On] in the case of a combined axial and re ial flow wheel (Figs. 1 and 3) an insignificant part of the water flows in a substantially radial direction into said wheel, as is indicated by the arrowsl. Having imparted its energy to the runner wheel, the water flows through the suction pipe into the waste, channel. Since a high specific number. of revolutions produces great discharge losses so called, it is clear that a suflicient recovery of energy must be proent of suitable suction'pipes. The working of said pipes may be improved by the utilization of the centrifugal forces of the .water. Therefore. a characteristic feature of my invention is the deflection of water into the bladeless space R whereby the major-portion or the entire amount of water ,changes its direction approximately ninety degrees, without the osses hitherto caused by the usual arrangement ofbla'd es in said space. l have found through theory and provided by experiments that such a deflection of fluid corresponds menses in all cases to the natural flow of fluid, or in other words, such a deflection occurs if the fluid entersa tube, without arrangement of special guide surfaces, and therefore a material reduction of losses caused byfriction can be obtained. Although in such a case the admission of water into the runner wheel cannot be realized without eddies and shock, especially near the turbine axis, still in many. cases such an arrangement can be advantageous by tending to prevent as far as possible the lowering of the efliciency if the admission of water changes from time to time. It is known for example, that in many turbine plants, the amount of water neededis not always available, and therefore if a large range of water consumption is required a-turbine having a lower maximum efliciency but a higher mean efficiency is superior to a turbine having a higher maximum efliciency but a lower mean efliciency. This superiority becomes the greater, the greater the difference between the maximum water supply and the minimum water supply.

Such a higher average efliciency can be obtained by the arrangement of the outlet edges of the guide vanes as described above. because in such a case, the lower edges oil said vanes do not materially guide the water into the runner wheel, and therefore if such guide vanes are. turned, the deviation of the a simple and inexpensive construction, and

also the working of theregulating means becomes easier, because the position of the vane bolts can be always chosen in-such a way,'that the resulting water pressure on said vanes can be applied near said bolts. This is of especial importance with automatical regulating devices.

' If the fluid not only in its course to the runner wheel, but also inthe spacesiof said wheel meets with those resistances, which result under all circumstances for the necessary' guiding of the fluid along the blades, it will be seen by such a flow that the raising of the specific number of revolutions can be increased to the limit-s of possibility. 'the usual-opinion that the fluid must be guided only in channel-shaped spaces (cells) cannot be maintained any longer.

In my application Serial Nr. 865,208 filed Oct. 5, 1914, l have'shown precisely that the peripheral length (Fig. 6) of a blade section (6 can be so-much reduced in comparison to the blade spacing t that the traspecific number of revolutions of the turbineof a clear width between two buckets doesnot exist, and therefore the blade spaces lose their usual cell-shaped form forming instead an elongated passage-way. Notwithstanding this change of form, a practical guidingot fluid can be arranged having the additional advantage, that the frictional resistances are materially reduced. The combination of a'series of such runnerblades with the bladeless space R allowing the-deflection: of fluid above described, results in the highest possible specific number of revolutions. r

' It is well-known, that many water courses cannot be utilized for the reason, that the hitherto reached is too small, and low speeds require expensive machinery and buildings. But according to my invention, .the utilization of such water courses is possible, because the increase in speed allows an economical working. But also in those cases, in

which an economical water supply is less important than the attainment of a high num-. her of revolutions, it must be admitted that if the specific speed of the turbine can be suitably increased, the utilizatidn of such water courses remains economical even with the smallest head. I

It is evident, that the advantages described aboi e do not depend on a strictly defined position of the outlet edges a, a of the guide vanes S The desired attainment of the natural deflection of the fluid can also be realized if the said edges are located-as shown by the broken lines a a '(Fig. 1), or if said edges are curved. Also it is immaterial whether said vanes are fixed or movable if at least the major part of fluid is deflected about ninety degrees in the bladeless space R,. The same holds good for the entrance edges (6 c, Fig. 1 and e e, Figs. 1, 2, 4 and 5) of the runner blades.

In my prior application Serial Nr 803,334 it is clearly shown that said deflection can always be attained if the outlet diameter D of the axial flow runner spaces R (Figs. 1,

3, 4 and 5) is suitably increased in relation.

to the outlet diameter D of the radial flow runner spaces R (Figs. 1 and 3), or if the latter spaces are wholly ornearly .wholly discarded (Figs. 4 and 5).

The form and shape of the bladeless space B, does not depend on a special curvature of the cover plate D.- This will be seen in Figs. 1 and 4 by the full lines representing a plain cover plate D and by the broken linesqepresenting a curved cover plate E- The latter allows the use of a suitable hearing of the runner shaft and increases the specific speed by reducing thev radial flow runner spaces asis indicated in Fig. 1 by 4. In a turbine the the modified wheel cover plate E shown in broken lines. In a twin turbine a hub substantially triangular in cross section may be arranged for the purpose of obtaining a suitable subdivision of the water flow, as is indicated in Fig.5 by the broken lines.

A turbine according to my invention can be utilized in all cases,'if a regular flow of fluid is obtained by suitable guide surfaces, both into the guide wheel and also into the runner wheel. Such a regular flow can be obtained not only with all kinds of turbines (water, steam, or gas turbine) but also with all kinds of modern turbine pumps or blowers. Also it is clear' that the guide Wheel and the runner wheel of said machines must be accommodated to the nature of the 1 driving means (liquid, steam, gas, or the like), without changing the characteristic features of my invention. Also it is clear, that the direction of the flow of fluid through the impeller. must be reversed, if my invention is adapted for a pump, and therefore the outlet edges of the pumps correspond .to the entrance edges of the turbines and conversely,

I claim as my invention: 1. In a turbine including a suction pipe the combination of a guide wheel and a runner wheel, the latter provided with sub stantially axial flow runner spaces, into which the fluid is admitted by a substantially radial flow guide wheel, the guide vanes thereon projecting slightly or not at all over the wall of the suction'pipe, thus providing a bladeless space in which the major part or the whole amount of fluid can be deflected about ninety degrees.

2. In a turbine including a suction pipe the combination of a guide wheel and a runner wheel, the latter comprising anupper and a lower set of runner blades forming" substantially axial flow blade spaces between each other into which the fluid is admitted by a radial flow-guidewheel, the guide vanes thereon projecting slightly or not at all over the wall of the suction. pipe, thus providing I of said pipe, thus providing a bladeless space in which the major part or the whole amount of fluid can be deflected about ninety degrees. i combination of a 'dis tributor for Francis-turbines, a suction pipe adapted fora suitable conversion of energy, and a runner wheel comprising a hub and aseries of substantially axial flow runner blades, the guidevanes projecting slightly or not at all over the wall of the suction pipe,

thus providing a bladeless space in which the major part or the whole amount of fluid can be deflected about ninety degrees.

5. In a -turbine including a suction pipe the combination of a gu de wheel, and a substantially axial flow runner wheel, the

latter provided with runner blades, the blade spacing of which is so arranged in relation to the true length of the blade profile, that an elongated passageway is formed, at least along a part of the blade surface, the guide vanes projecting slightly or not at all over the wall of the said suction pipe, thus providing a bladeless space in which the major art or the whole amount of fluid can be deflected about ninety degrees.

6. In a turbine including a suction pipe the combination of a guide wheel, and an impeller, the latter comprising a hub and a series of substantially axial flow impeller blades, arranged round said hub and rigidly true length of the blade profile, that an elongated passageway is formed, at least along a part of the blade surfaces, the guide vanes projecting slightly or not at all over the wall of the said suction pipe, thus providing a bladeless space in which the major part'or the whole amount of fluid can be deflected about ninety degrees.

In testimony whereof I have hereunto set my hand in the presence of two subscribing w1tnesses,

PROF. DR. ING. VICTOR KAPLAN. Witnesses KARL KISLINGER, HUGO THORNE. 

